 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.resource.ImageRegistry;
 import org.eclipse.ui.internal.util.PrefUtil;
 import org.eclipse.ui.plugin.AbstractUIPlugin;
 import org.osgi.framework.BundleContext;

 /**
  * The plug-in class for the org.eclipse.ui plug-in.
  * This class is internal to the workbench and should not be
  * referenced by clients.
  */
 public final class UIPlugin extends AbstractUIPlugin {

     private static UIPlugin inst;

     /**
      * Creates an instance of the UIPlugin.
      *
      * @since 3.0
      */
     public UIPlugin() {
         super();
         inst = this;
     }

     /**
      * Returns the image registry for this plugin.
      *
      * Where are the images? The images (typically gifs) are found in the
      * same plugins directory.
      *
      * @see ImageRegistry
      *
      * Note: The workbench uses the standard JFace ImageRegistry to track its images. In addition
      * the class WorkbenchGraphicResources provides convenience access to the graphics resources
      * and fast field access for some of the commonly used graphical images.
      */
     protected ImageRegistry createImageRegistry() {
         /* Just to be sure that we don't access this
          * plug-ins image registry.
          */
         Assert.isLegal(false);
         return null;
     }

     public ImageRegistry getImageRegistry() {
         /* Just to be sure that we don't access this
          * plug-ins image registry.
          */
         Assert.isLegal(false);
         return null;
     }

     /**
      * Returns the default instance of the receiver. This represents the runtime plugin.
      *
      * @return UIPlugin the singleton instance of the receiver.
      * @see AbstractUIPlugin for the typical implementation pattern for plugin classes.
      */
     public static UIPlugin getDefault() {
         return inst;
     }

     /**
      * Set default preference values.
      * This method must be called whenever the preference store is initially loaded
      * because the default values are not stored in the preference store.
      */
     protected void initializeDefaultPreferences(IPreferenceStore store) {
         // Do nothing. This should not be called.
 // Prefs are initialized in UIPreferenceInitializer.
 }

     /* (non-Javadoc)
      * @see org.eclipse.ui.plugin.AbstractUIPlugin#start(org.osgi.framework.BundleContext)
      */
     public void start(BundleContext context) throws Exception {
         super.start(context);

         // set a callback allowing the workbench plugin to obtain
 // and save the UI plugin's preference store
 PrefUtil.setUICallback(new PrefUtil.ICallback() {
             public IPreferenceStore getPreferenceStore() {
                 return UIPlugin.this.getPreferenceStore();
             }

             public void savePreferences() {
                 UIPlugin.this.savePluginPreferences();
             }
         });
     }
 }

